1. Buy your wood in 24" x 1.5" x 1/8" pieces. One online place is
Rockler (click here), and they have a store locater -- stores in many large cities. $4 will get you enough for 4 sets of scales.
2. Go to Hobby Lobby or Home Depot and get a coping saw. $10-15. Home Depot has a variety of different sizes. Or get one at
Rockler here.
3. When you get to the point where you have two pieces of wood rubber-cemented together, with the scale outline drawn, rough-cut as close to the line as is easy with the coping saw.
4. Use your Dremel tool with a 1/2" sanding drum (120 grit) and just carve away the wood right up to the line. Practice first on some scrap, it goes really fast! Use light pressure, keep moving so you don't burn the wood.
5. You can then use one of those Dremel "puff-buffs" at 320 grit to round off the square edges a little and get closer to your desired shape. The rest is going to be hand-sanding anyway.